Abstract

Using a scattering matrix approach and quasiclassical Green's function technique, we calculate the conductance of the superconductor-normal-metal (S/N) system (see Fig. 1). We establish that the difference between the superconducting and normal state conductance (delta G=G(s)-G(n)) is negative for large S/N interface resistances (R-S/N) and changes sign with decreasing R-S/N. [S0163-1829(98)03742-4].